Pets give joy to millions of people around the world. They can live long lives and even grow up alongside children. Cats, for example, can live to be more than two decades old, all the while climbing, jumping and playing up until the point when they are nearly too old for such activities. However, not all cats appear to have the same vigor throughout their later years. Specifically, adult cats of any age are known to spend most of their time sleeping, eating and then sleeping some more. This could indicate that something may not be right with the cat, and is statistics suggest the problem might be that the cat is overweight.
There are a number of factors contributing to a rise in feline obesity. One factor is that more cats are becoming indoor cats and, as such, they are not getting as much exercise as outdoor cats. Another factor may be boredom, and the ubiquitous practice of pet owners leaving food out at all times may cause eating from boredom as well as hunger. With that being said, many owners overfeed their cats, either because their cats beg for food, or because they do not have a clear idea of just how little food cats really need. As few as six extra pieces of kibble in a single meal may contribute to a cat gaining unwanted weight.
The consequences of feline obesity are serious. Excess body weight may cut a pet's life short. For instance, the risk of death for middle-aged obese cats is nearly three times greater than for cats at their ideal weight. Some studies show that obesity is a risk factor for diabetes mellitus, skin problems, hepatic lipidosis, and lameness. Cats who are overweight are also at increased risk for conditions such as urinary tract disease, problems with anesthesia and other drugs, respiratory difficulty, heat intolerance, impaired immunity, and skin problems. The same applies to dogs (canine obesity) and other pets, generally.
The first step in approaching weight loss in homes with pets is to switch from free-feeding to meal-feeding. This means dispensing the pets' food at a certain number of times per day, then picking up the uneaten food or dirty bowls after the pets have had a chance to eat. However, this can be burdensome to the pet owner, for example, if the pet owner's schedule is unpredictable or if the pet owner travels frequently. Another problem arises when a home has multiple pets, where a pet owner may also have to separate those pets from each other and feed each pet by itself.
One specific problem arises when one or more pets have a special dietary need, such as a home that has a pet that is overweight and/or a pet that is underweight. Without carefully regulating the activities of the two pets or placing the food in different locations for different pets, there is nothing that prevents the overweight pet (or any other animal in the home) from eating the food of the underweight or normal weight pet. One solution to this problem is the use of transmitters to permit and deny access to the food dish. Examples of such transmitters are described by Matsuura et al. in U.S. Pat. No. 6,044,795 entitled, AUTOMATIC FEEDING SYSTEM HAVING ANIMAL CARRIED TRANSMITTER WHICH TRANSMITS FEEDING INSTRUCTIONS TO FEEDER, issued Apr. 4, 2000, as well as Bickley in U.S. Pat. No. 6,446,574 entitled ANIMAL-ACTUATED FEEDER, in addition to Clarke in U.S. Pat. No. 7,124,707 entitled SELECTIVE ANIMAL FEEDING APPARATUS, issued Oct. 24, 2006. The advantage of using such a device, much like an electronic key, is that only one pet may be in possession of such a transmitter and, accordingly, gain access to the food. For example, if there is an overweight pet living with a healthy pet, the healthy pet may have a transmitter, e.g., on its collar, that allows it to gain access to its food when the transmitter comes in close proximity with a receiver. This would prevent the heavier pet from eating the healthy pet's food. A disadvantage of these systems is that they either still require the owner to manually feed the pet, or if food is dispensed automatically, the dispensed food will not include the precise measurement of food required for a healthy diet.
Attempts have been made to overcome the necessity to manually feed pets by using automated feeders, such as the one described by Krishnamurthy in U.S. Pat. No. 6,401,657 entitled, AUTOMATIC PET FOOD FEEDER, issued Jun. 11, 2002 and by Turner et al., in U.S. Pat. No. 7,228,816 entitled ANIMAL FEEDING DEVICE AND METHOD. Such devices use gravity and a rotating auger or screw shaft, which, when rotating, moves food out of a tube into a feeding bowl. One advantage of such devices is that the device automates the feeding process by measuring the amount of food to dispense based upon how many rotations are completed and can be programmed to dispense the food at certain times. However, the disadvantage is that the technique used to measure the food is too inaccurate. For example, as noted above, if as few as six extra pieces of kibble in a single meal may make a pet gain unwanted weight, the screw shaft may be distributing excess amounts of food depending on such factors as the size of the kibble, the size of the screw shaft, how many pieces of kibble are caught in the screw shaft, and the number of times in a day the feeder operates. For instance, some rotations of the screw shaft may catch and dispense 6 pieces of kibble, while 8 pieces of kibble may be caught and dispensed during the next rotation, etc. Additionally, if the pet has not eaten all of the previously dispensed food, the automatic feeder will continue to dispense the same amount of food, thus overflowing of food and over feeding may continue to occur.
One technique, like the one described by Vittuari et al., in U.S. Pat. No. 6,145,472 entitled, AUTOMATIC FEED DISTRIBUTION APPARATUS FOR ANIMALS, issued Nov. 14, 2000, attempts to correct the overflow problem by incorporating an angular potentiometer to determine if there is leftover food the pet has not eaten. For example, a bend allows a detector to lower down to touch the bottom of a food trough (i.e., food dish). The angular movement of the rod would indicate that food is remaining in the food dish. The greater is the angular movement of the rod, the less food that exists in the dish. With this information, the amount of food to be dispensed in the food dish can be tailored based on the leftover food. The advantage of such a system is that it avoids food overflow. However, one disadvantage that remains is the inaccuracy of using a volumetric screw feeder, similar to the ones used in the above-mentioned patents. A second disadvantage is the questionable accuracy of the angular zo potentiometer to precisely determine how much food remains in the food dish. For example, similar to how a car's gas gauge may only estimate the approximate gas level in a gas tank, the angular movement of the rod is only a rough estimation of the amount of food remaining in the food dish. Furthermore, there may be more food in one area of the food dish that is not identified by the rod which is touching a different area of the food dish. Thus, such a system still fails to address the problem of continuously dispensing a healthy amount of food.
Due to the enumerated health risks associated with overweight pets, it is essential that a pet's weight loss be slow and steady. For example, the weight loss should not exceed 2 percent of body weight per week, which for a 15 pound cat is approximately one or two ounces. Furthermore, like people, animals vary between one another and thus their dietary needs may vary as well due to such things as weight, age, activity levels, etc. Thus, because as few as six extra pieces of kibble in a single meal can make a pet gain unwanted weight, and because a pet's weight loss should be gradual and specific to an individual pet, there remains a need for an automatic food dispensing system and method that prevents one or more pets from eating a particular pets' food, but that also dispenses an appropriate amount of food in a way that is carefully determined (e.g., tailored to the pet) and measured for optimal dietary feeding.